Friday, May 6, 2016

Geotechnical Engineering #13 - Final, Public Safety and Engineering

It is now obvious that my favourite geotech job is a ghost-town, probably cited for a zillion osha violations.

On to the secondary title. Since Brunel, it has been found that engineers design for 1 in 10,000 per year chance of death. That gives a good chance that a design (like a bridge or tunnel) won't fail during the engineer's lifetime. It's engrained in the fibre of their beings. On the other hand, 'People of Undefined Intelligence' or 'workers' are perfectly happy with 1 in 100 per year chance of death. Workerism is fine with low populations who don't read, but once a society gets complex, it becomes unacceptable. In Canada, at these odds, we'd have lots of worker deaths per day. Everybody would have anxiety issues and lock themselves up in a dark room. The economy would die. Commercial airlines are 1 in 10 million, because people are very sensitive about that, and could choose not to fly.

We can't have that, so safety regulations try to bring it up (down) to engineering levels. For a window washer, there is a 1 in 100 chance of failure of his main system. Add a safety system, and there is a 1 in 100 chance of that failing when called upon. Two such independent systems, put together, gives you 1 in 10,000.

Since no workers would do it themselves, this requires legislation, and a heavy hand in enforcement. Most things are up there now, except scaffolding - yuck.

Right from the beginning the geotech job was a 'handy man special' (which our nuclear plants are full of), which gave it 1 in 100 chance of death. I was appalled and treated it as a fantasy. I like to think that the Ministry came upon it by accident, and had nothing to do with me. Otherwise my 'kills' list would be huge. :)

I remember the Niagara Tunnel was like this, but they squeaked through. Our nuclear plants have been thoroughly infected with 'workerism', and so has our emergency response system. The odds of death by earthquake are at 1 in 500. I only consider factors of 10 to be significant here.

So, all you thrill-seekers who dodge in and out of traffic on the 401, take over engineering design. We'll see what happens.

ps. Lest you think engineers are gods, remember that over a hundred years lifetime, the odds of being tagged for death in a design are 1 in 100. And when we engineers do work at home or the cottage, we go totally with 'workerism'. :)

pps. I gave this story to the CBC. Not apparently interested, even though it will cost millions.

UPDATE: Today (Monday) they are back to work like nothing happened. They are draining the undrainable pit with a bigger pump and back to the original plan. The series continues!